Subject: [PATCH AUTOSEL 5.1 092/219] net: hns3: fix for dereferencing before null checking

From: Sasha Levin <[email-masked]>
Date: Mon, 15 Jul 2019 10:01:33 -0400

From: Yunsheng Lin <[email-masked]>

[ Upstream commit 757188005f905664b0186b88cf26a7e844190a63 ]

The netdev is dereferenced before null checking in the function
hns3_setup_tc.

This patch moves the dereferencing after the null checking.

Fixes: 76ad4f0ee747 ("net: hns3: Add support of HNS3 Ethernet Driver for hip08 SoC")

Signed-off-by: Yunsheng Lin <[email-masked]>
Signed-off-by: Peng Li <[email-masked]>
Signed-off-by: Huazhong Tan <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
index cac17152157d..6afdd376bc03 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
@@ -1497,12 +1497,12 @@ static void hns3_nic_get_stats64(struct net_device *netdev,
 static int hns3_setup_tc(struct net_device *netdev, void *type_data)
 {
 	struct tc_mqprio_qopt_offload *mqprio_qopt = type_data;
-	struct hnae3_handle *h = hns3_get_handle(netdev);
-	struct hnae3_knic_private_info *kinfo = &h->kinfo;
 	u8 *prio_tc = mqprio_qopt->qopt.prio_tc_map;
+	struct hnae3_knic_private_info *kinfo;
 	u8 tc = mqprio_qopt->qopt.num_tc;
 	u16 mode = mqprio_qopt->mode;
 	u8 hw = mqprio_qopt->qopt.hw;
+	struct hnae3_handle *h;
 
 	if (!((hw == TC_MQPRIO_HW_OFFLOAD_TCS &&
 	       mode == TC_MQPRIO_MODE_CHANNEL) || (!hw && tc == 0)))
@@ -1514,6 +1514,9 @@ static int hns3_setup_tc(struct net_device *netdev, void *type_data)
 	if (!netdev)
 		return -EINVAL;
 
+	h = hns3_get_handle(netdev);
+	kinfo = &h->kinfo;
+
 	return (kinfo->dcb_ops && kinfo->dcb_ops->setup_tc) ?
 		kinfo->dcb_ops->setup_tc(h, tc, prio_tc) : -EOPNOTSUPP;
 }
-- 
2.20.1